Upgrade IOS on cisco voice gateways

[Syed]

Dear All,

I would like to upgrade IOS on a couple of 3945 routers. Find below hardware info and suggest the latest IOS to go with, please.

Current IOS Version: c3900-universalk9-mz.SPA.150-1.M1.bin

Cisco CISCO3945-CHASSIS (revision 1.0) with C3900-SPE150/K9 with 972800K/75776K bytes of memory.

DRAM configuration is 72 bits wide with parity enabled.

255K bytes of non-volatile configuration memory.

254464K bytes of ATA System CompactFlash 0 (Read/Write)

Also, I do not want to delete the current IOS but would like to switch over to the new version, kindly help me as to how I could achieve this task.

Thank you in advance.

Regards,

Syed

[Aman Soi]

Hi Syed,

Firstly , u need to check the size of existing flash so that it can accommodate two images.

If the size is available, then , u can upload it and boot the router with new image using command boot system flash0:

http://www.cisco.com/c/en/us/td/docs/ios/12_2/configfun/configuration/guide/ffun_c/fcf008.html

regds,

aman

[Syed]

Hi Aman,

Find the flash memory details and advise whether I can have two images or ?

199802880 bytes available (60370944 bytes used)

Thank you

[Aman Soi]

Hi Syed,

Your flash total size is 260MB [summing both available and used]

if your new image is not exceeding 199802880 bytes , then, u can upload new image and boot the router with it.

regds,

aman

[Leo Laohoo]

Syed, 

1.  Copy the IOS into the router;

2.  Compare the MD5 hash of the file against the MD5 hash found in the Cisco website; 

3.  Change the boot variable string:  Instruct the router to boot the new IOS first and then boot the old IOS (in case the first IOS fails to boot). 

PS:  While you're in the midst of upgrading the IOS, consider upgrading the bootstrap.